Submission #1109526

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109526		vjudge1	Pohlepko (COCI16_pohlepko)	C++17	70 / 80	64 ms	17760 KiB

pohlepko

#include <bits/stdc++.h>
#define F first
#define S second
#define LL long long
 
#define rep(i, x) for(auto &i : (x))
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
 
#define left(x) ((x)<<1)
#define right(x) ((x)>>1)
#define LSOne(x) (x & -(x))
 
using namespace std;
using T = pair<pair<int,char>, pair<int, int>>;
 
const int SZ = 2e3 + 1;
const LL MOD = 1e9 + 7; 
const LL INF = 1e18 + 1;
 
LL bp (LL b, LL e, LL m = MOD) {
 if ( e == 0 ) return 1;
 LL T = bp(b, e / 2);
 T *= T; T %= m;
 if ( e & 1 ) T *= b;
 return T %= m;
}
 
LL nv_i (LL a) { return bp(a, MOD - 2); };
LL gcd (LL a, LL b) { return (b == 0 ? a : gcd(b, a % b)); }
LL lcm(LL a, LL b) { return (a * (b / gcd(a, b))); }
LL ceil (LL a, LL b) { return ((a + b - 1) / b); }
 
vector<vector<char>> G;
vector<vector<bool>> VIS;
vector<char> LETTERS;
int n, m, mx = 0;

void bfs() {
  queue<T> Q;

  Q.push({{1, 'z' + 1}, {1, 1}});

  while(!Q.empty()) {
    int dist = Q.front().F.F, i = Q.front().S.F, j = Q.front().S.S, prev_l = Q.front().F.S;
    Q.pop();

    if(VIS[i][j] || i > n || j > m || LETTERS[dist - 1] != prev_l) continue;
    VIS[i][j] = 1;
    
    LETTERS[dist] = min(LETTERS[dist], G[i][j]);
    mx = max(mx, dist);
    Q.push({{dist + 1, G[i][j]}, {i + 1, j}});
    Q.push({{dist + 1, G[i][j]}, {i, j + 1}});
  }
}

void solve() {
  cin >> n >> m;
 
  G.resize(SZ, vector<char> (SZ));
  VIS.resize(SZ, vector<bool> (SZ));
  LETTERS.resize((SZ) * (SZ) + 1, 'z' + 1);

  for(int i = 1; i <= n; i ++) {
    for(int j = 1; j <= m; j ++) {
      char x;
      cin >> x;
      
      G[i][j] = x;
    }
  } 

  bfs();

  for(int i = 1; i <= mx; i ++) {
    cout << LETTERS[i];
  }
}
 
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);
 
  solve();
  return 0;
}

• Subtask 1: 70 / 80